Mazda B Series MOT Failures
An analysis of 45,007 real DVSA MOT tests on the Mazda B Series — what fails, how often, and how that compares to every other car on UK roads. Generations covered: UF (1998–2006), UN (2002–2013).
Where the Mazda B Series fails its MOT
The single biggest MOT failure point on the Mazda B Series is coil springs broken — this model is 216 times more likely to fail on this item than the average car on UK roads. That makes it an extreme outlier for anyone buying or owning this model. Across 45,007 MOT tests, 4.7% of all Mazda B Series tests recorded this as a failure.
Suspension failures typically mean worn bushes, drop links, or dampers. These affect handling and tyre wear. Budget £150–£400 per corner at an independent garage for full suspension overhaul.
Other notable weak points include free play in the steering, measured at the rim ... (200x the fleet average), load sensing valve seized or inoperative and ab... (190x the fleet average), fixings missing or insecure (226x the fleet average), and obligatory rear fog lamp missing, or a front or... (48x the fleet average). These ratios compare the Mazda B Series's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 5 categories: Suspension, Steering, Brakes, Bodywork, Lights & Electrics. If you're inspecting a Mazda B Series before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Mazda B Series's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Mazda B Series specifically, the DVSA data shows the most common failures at this mileage are coil springs broken (216x the average) and structural corrosion (69x). body, cab or chassis corroded at a mounting point (58x) and obligatory rear fog lamp missing, or a front or... (23x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Mazda B Series specifically, the DVSA data shows the most common failures at this mileage are fixings missing or insecure (226x the average) and free play in the steering, measured at the rim ... (200x). load sensing valve seized or inoperative and ab... (190x) and coil springs broken (124x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Mazda B Series specifically, the DVSA data shows the most common failures at this mileage are free play in the steering, measured at the rim ... (120x the average) and load sensing valve seized or inoperative and ab... (89x). fixings missing or insecure (76x) and coil springs broken (48x) also appear frequently.
The shift from coil springs broken at lower mileages to free play in the steering, measured at the rim ... at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Mazda B Series specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Chassis and body mounting point corrosion (UF/UN) Dangerous
The B Series suffers extensive corrosion at critical structural mounting points where the body meets the chassis frame. Affects UF, UN; typical independent garage repair cost is £800–£2,000.
Structural chassis corrosion (UF/UN) Dangerous
The separate chassis design of the B Series is highly susceptible to structural corrosion that compromises the vehicle's rigidity and safety. Affects UF, UN; typical independent garage repair cost is £1,500–£4,000.
Suspension component excessive wear (UF/UN) Major
The B Series shows exceptional wear rates in suspension bushes, pins, and joints, with MOT data indicating failure rates over 216 times the national average. Affects UF, UN; typical independent garage repair cost is £300–£800.
Steering play excessive (UF/UN) Major
The B Series steering system develops excessive free play at nearly 200 times the national fleet average, typically manifesting from 60,000 miles onwards. Affects UF, UN; typical independent garage repair cost is £200–£400.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Mazda B Series common problems breakdown.
What to check before buying a Mazda B Series
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Mazda B Series:
Suspension — check for coil springs broken. Steering — check for free play in the steering, measured at the rim .... Brakes — check for load sensing valve seized or inoperative and ab.... Bodywork — check for fixings missing or insecure, body or cab insecure, abs fault, body, cab or chassis corroded at a mounting point.
Beyond the MOT items, ask specifically about chassis and body mounting point corrosion and structural chassis corrosion. These won't show up on a standard MOT but can be expensive to fix — repairs start from £800. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Mazda B Series?
Enter the reg to see its full MOT history, mileage records, write-off status, and finance checks.
Mazda B Series MOT FAQs
What are the most common MOT failures on a Mazda B Series?
Based on 45,007 DVSA MOT tests, the most common failure is coil springs broken — at 216x the national fleet average. Other frequent failures include free play in the steering, measured at the rim ... and load sensing valve seized or inoperative and ab....
Is the Mazda B Series reliable based on MOT data?
The Mazda B Series has 15 MOT failure categories above the fleet average. Specialists also flag chassis and body mounting point corrosion as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Mazda B Series most commonly fails on free play in the steering, measured at the rim ... and load sensing valve seized or inoperative and ab.... Under 60,000 miles, the main issues are coil springs broken and structural corrosion.
How do I check a Mazda B Series's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.